Railway traffic-controlling apparatus and system.



PATENTED JULY 31,- 1906.

No. 827A411.

. H.BBZER. v RAILWAY TRAFFIC CONTROLLING APPARATUS AND SYSTEM.

APPLICATION FILED JAN. 28 1905.

2 SHEETS-SHEET 1.

wN *N N l/VVE/VTUR ATTORNL'Y I WITNESSES:

THE NORRIS PETERS L0,, wnsmuaro". 04 c.

No. 827,411. PATENTED JULY 31, 1906.

- H. BBZER. RAILWAY TRAFFIC GONTROLLING'APPARATUS AND SYSTEM.

urnmuxon rum) m. as. 1905.

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THE NORRIS PETERS 50-. WASHINGTON, a c.

- name sTArEs PATENT omen.

HENRY BEZER, OF WESTFIELD, NEW JERSEY.

RAILWAY TRAFFIC-CONTROLLING APPARATUS. AND SYSTEM.

To all whon t it newt/concern:

Be it known that I, HENRY BEZER, asubject of the King of Great Britain,residing at Westfield, in the county of Union and State of New Jersey,haveinvented certain newand'useful Improvements in Railway Trafiic-Controlling Apparatus whichthe following is a specification, referencebeing had therein to the accompanying drawings, forming'a part thereof;

My invention relates, broadly, to railway traffic-controlling apparatusand systems,

and may be embodied in traffic-controlling apparatus and systems whichcontrol railway trafiic upon a railway-line by the display of visualsignals, as in the instance of railway block-signaling apparatus andsystems, such as illustrated in the accompanyingdrawings,

representing two embodiments of my invenvisual-signal system by thedisplay of one or more danger'or blocking indications.

Also certain embodiments and certain features of my invention relateparticularly to that class-of railway trafiic-controlling apparatus andsystems which employ directional variations of controlling electriccurrent in a controlling-circuit to govern and determine the conditionor indication of the apparatus. My invention also includes certainfeatures relating particularly to that class of railwaytraffic-controlling apparatus and systems wherein variations inresistance or conductance of a controlling electric circuit are employedto actuate or govern actuation of the traflic-controlling apparatus.

Broadly set forth, the objects ofmy inventionv are reliability ofoperation to insure the safety of traflicupon the railway-line andeconomy and simplicity of construction and maintenance in the greatestdegree compati- 1 ble with such safety. For the attainment of thesebroad ends my invent-ion is capable of embodiment in various forms ofconstruction and arrangement of its component elements and comprehendsmany particular features and many objects subservient to theforego-Specification of Letters Patent.

Application filed January 23,1905. SerlalNO- 242.303.

and Systems, of

Patented Jfuly 31,1906,

ingbroad ends, but capable of more'particular designation, and all thesefeatures and objects appear in the light of the particular descriptionof those two embodiments of my invention which areillustrated intheaccompanying drawings, although I will at this point separatelymention various but not all of these particular objects and features.

In-i ts application to home and distant rail way block-signaling systemsor apparatus responsivet-o and'controlled by directional variation ofcontrolling-current in a signalcontrolling circuit itis one object of myinvention to maintain the signaling apparatus in normal danger or normalblocking por-' tion or condition, thisbeing much safer practice than-thenormal clear-or unblocking-condition in which-such home and distantdirectionally-responsive signals have heretofore been maintained. Tothis-end my invention comprehend's the combination of'a railwaysignalingor signal-controlling circuit which will generally .becontrolled automatically by the presence of railway-vehicles upon therailway-line, a suitablesource of reversible signal-controllingcurrentfor the signaling-cu cuit, a railway signaling apparatus responsivetodirectional variation of'signaling-current and controllable by thesignaling-circuit to give both home and distant signal indications, andmeans-such, forinstance, as-an- I other signal-controllingcircuit-governable by approach of a railway trainorvehicle-formaintaining the signaling apparatus normally inits dangercondition to arrest traffic and for clearing the signals as the train orrailway-vehicle approaches them-in other 'WOI'dS,. the combination of asignal-controlling circuit including a source of reversiblesignaling-current and normal danger home and distantelectrically-controllable directionally-responsive railway signalingapparatus subject to control of the signaling-circuit.

In its adaptation to railway traflic-controlling systems wherein certainapparatusis controlled by conductance or resistance variations in anelectric traffic-controlling circuit my invention has the further objectof compensating or counteracting the eflect's controlling'circuit, butrequired to be nonresponsive to such variations; To this endmyinven-tion comp'rehends the: combination of such conductance orresistance variations upon certain other apparatus ofthe system T alsosubject to the influence of the trafficfro of a railwaytraffic-controlling electric circuit of variable conductance orresistance, a railway traffic-controllingapparatus controllable by suchtraffic-controlling circuit and responsive to variations in itsconductance or resistance, another railway trafliccontrolling apparatusalso controllable-by the traffic-controlling circuit and responsive totrafiic-controlling current therein, and means for effecting theconductance or resistance variations required to actuate the firsttrafiic-controlling apparatus and for compensating the effects of suchconductance or resistance variations upon the second traffic-controllingapparatus. The illustrated embodiments of the foregoing feature of myinvention consist in a railway trafliccontrolling system including arailway traflic-controlling apparatusl located at a giventrafiic-controlling poi nt' in proximity to a railway-line, atraflic-controlling electric circuit in control of thetrafiic-controlling apparatus and in theseparticular instances includingthe traflic rails of the railway-line, and another orsecondtraffic-controlling apparatus located at anothertraflic-controlling point in proximityto the railway-line and comprisingtwo traific-controlling electro- 'translative conductorsthat is to say,conductors adapted to respond to a traflic-controlling current orcurrent impulse from the traffic-controlling circuit, so as to give riseto another impulse of energy, such as another current impulse ora-mechanical movement for controlling or actuating thetraflic-controlling apparatusand means for including a given one of thetrafiic-controlling electrotranslative conductors in thetraffic-controlling circuit after the other traffic-controllingconductor has been included therein, such given electrotranslativeconductor last introduced into circuit being adapted by suchintroduction to vary the conductance or resistance of thetrafiic-controlling circuit, so as to actuate the firsttraffic-controlling apparatus, and such given conductance-varyingelectrotranslative conductor also being cooperative with the othertraflic-controlling electrotranslative conductor to compensate orcounteract the eiiects thereon of current perturbation due to suchconductance variation, so that the firsttrafiie-controlling apparatusmay becontrolled and actuated without affecting the secondtraflic-controlling apparatus.

In, its adaptation to that class of railway traffic-controlling systemswherein an electri'c traffic-controlling circuit isv employed to control,traffic-controlling apparatus at two trafiic-controlling points inproximityito the railway-line and wherein one or more electrotranslativeconductors are introduced into thetraflic-controlling circuit at one .ofthe traffic-controllingpoints in order to varythe conductance orresistance of such circuit, so

swan

as to actuate the traflic-controlling appara-' tus at the other point, afurther object of my invention is to utilize such an electrotranslativeconductor not only as a means for varying the conductance or resistanceof the traffic-controlling circuit, so as to actuate thetrafficcontrolling apparatus at the other traffic-controlling point, butalso to utilize such an electrotranslative conductor for responsivenessto directional variation of traific-controlling current in thetraIiic-controL ling circuit in order to control the traflic-controllingapparatus at the point where such translative conductor is located. Tothis end my invention comprehends the combination of a railwaytraflic-controlling apparatus located at a given tIiLfiIC-COlltlOlllDgpoint in proximity to a railway-line and connected with atrafiic-controlling electric circuit and responsive to conductance orresistance va-,

line and including an electrotranslative con-' ductor responsive todirectional variation of traffic-controlling current and arranged incontrolling relation to such second apparatus and means for connectingsuch electrotranslative conductor in the traflic-controlling circuit soas tovary its conductance or resistance and actuate the first-mentionedtraffic-controlling apparatus.

In its application to railway illtt'IfiG-(JOH- trolling systems whereinrailway trailic-controlling apparatus is controlled by conductancevariation in a tiaflic-controlling electric circuit it is a furtherobject of my invention to compensate the variation in influence of anelectrotranslative conductor or magnet due to an operation of thetrafiic-controlling apparatus effected by response of suchelectrotranslative conductor to a given conductance variation in thetraffic-controlling.

the magnet on the armature with a given strength of current, and hencerequire an in, verse conductance variation greater than the initialconductance variation in order to return the armature to its initialposition, and it is therefore necessary to compensate the variation inthe influence of the electrotranslative magnet due to movement of itsarmature in order that the same may be returned r to initial position.In the illustrated embodiments of my invention this variation in theinfluence of the magnet, due to movement of its armature, is compensatedby a compen- ,sative conductance variation in the tralficcontrollingcircuit which is inverse to the actuative conductance variationproducing sucharmature-movement, so that the compensative inverseconductance variation, together with another conductance variation which1s lnverse and, 1f desired, equal-to the first actuative conductancevariation, will aggregate an inverse conductancevariation,

which exceeds the first actuative conductance variation in a degreesufficient to effect. retractive movement of the armature.

Those objects and features of my invention which have notbeenparticularly. andfiseparately mentioned in the foregoingpreamblewill clearly appear in the light of the following more detaileddescription of my inven-- tion embodied-in two railwaytraffic-controlling systems,,which I have illustrated in theaccompanying drawings.

The normal danger railway block-signaling system diagrammed inFigure 1comprises normal dangerrailway signaling apparatus thereof.

railway train or vehicle is passingthrough.

located in proximity to the adjacent ends-of" successive railway-blocks,and the diagram indicates three such railway-blocks (marked B, B and Bin the order in'whicha railwaytrain passes through them. The adjacentends of the rails ofsu'ccessive railway-blocks are insulated from eachother in awell-known manner, asindicated. The normaldanger signalingapparatus located inproximityto the advance end of the block B andtherear end of the next block in advance B is char acteristic of theapparatus similarly located throughout the system and may be taken as anexample. Eachsuch normal danger-rail 'way signaling apparatus comprisesnormal danger railway signalingmeans proper, such:

.in advance thereof, andleach distant-signal semaphore, suchas D,indicates the-condition of the railway-block secondinadvanceNormallythat is to say, when no any railway-block affecting thesignal-semaphores-the home-signal and distant-signal. semaphores areintheir danger positions that is to say, their positions indicating thenon-clear conditions of their respective railway-blocks. The home-signalanddistantsignal semaphores, such as H and D, are con-v trolled,respectively, I by. home. and distant.

semaphore-actuating magnets, such as h and d, by means of any oneofvarious forms of actuative mechanism well known to the sig naling art;and not shown in the diagram, such actuative mechanism being cooperativewith the semaphore-actuating; magnets and their signal-semaphores, so asto -mo.ve the home-signal. and distant-signal semaphores H- and'D totheir clear'positionswhen their respectivesemaphore-actuating magnetsare energized and. suchv mechamsms further coterweights or othersuitablemeans to their danger positions when their respectivesemaphore-actuating magnets are deenergized. suchactuative mechanlsm orits home semaphore actuating magnet is, preferably designed forslow-acting operation, according to well-known principles, so that amomentary cessation of current in the home-semaphoreactuating magnetwill not cause its home-siginal semaphore to assume danger position solong as the duration of such cessation does not exceed a certain periodof retention during which the semaphore will be retained from assumingits danger position.

In the embodiment of my invention diagrammed in Fig. 1 each signalingapparatus located in proximity to the adjacent advance and. rear ends oftwo successive railwayblocks comprises a semipolarized rear track relayor translating apparatus (generally designatedby X) anda non-polarizedadvance track relay or" translating apparatus (designated generally byY.)- The semipolarized rear track relay or translating device Xcomprises two outer coils or home clearing coils E in series with eachother, and two inner coils, or home and distant clearing coils F inserieswith each other, all four coils being mounted upon magnetic coressecured to a common back iron or yoke, such as 53. The cores and theircoils are preferably placedall in line, as indicated in the diagram, inorder to'present the polar extremities of all four corestoward a commonstraight-bar armaturexwhich may be located beneath the polar extremitiesand subjected to the attractive forces of all, four ofthe coils jointly.This armature is termed the main armature,

and for the sake of clearness it has been omitted-from the. diagram. Itis suitably connected with contact-fingers m and 0 in such IIO mannerthat whenthe armature is attracted V toward the coils of'the relay X itwill move these contact-fingers into positions of contact with their.respective contact-stops n and 12., The main armature is normallyretracted by gravity or other suitable retractive force away from itsposition of nearest approach to the magnet, so as to maintain itscontact-fingers m and 0 normally in'noncontacting positions. The polarends of the cores of the inner relay-coilsF are provided with horizontalpolar extensions 49, extending at rightangles to the cores of the coilsand, as seenin Fig. 1, toward the observer. Apermanently-polarizedmagnetic core, such as 48, secured to the middle ofthe back iron53,extends downward in parallelism with the coresof the relay-coils andconstitutes the permanent magnet of the semipolarized relay. Upon the.lower end of this permanently-magnetized core 48 a polarized armature jis pivotally mounted, so as to swing close to the extremities of and inthe plane of the horizontal polar projections 49, such plane beingnormal to the plane of the relay-coils E and F and substantially normalto the plane of movement or direction of movement of the main armatureof the relay. When the horizontal polar projections 49 are magnetizedwith one certain direction of polarity by energization of the cores ofthe home and distant clearing coils F, due to passage of current throughsuch coils in one certain di rection, which may be termed the distantclearing direction, the polarized armature j is caused by suchmagnetizing eflect of the home and distant clearing coils F to oscillateabout its pivotal center, so as to bring its opposing ends into contactwith their respective contact-stops k and i. Current in the oppositedirection through the home and distant clearing coilsF only tends toswing the polarized armature j in the opposite direction and out ofposition of contact with its contact-stops. Such non-contacting positionis the normal position of the polarized or distant-signalclearing-armature j and is further assured by suitable retractive meanswhich are not shown in the diagram, but which tend always to move thepolarized armature into its non-contacting position.

The home and distant clearing advance track-relay or translating deviceY comprises a home and distant clearing front magnet including two homeand distant clearing front coils J and two home clearing front coils K,and such advance track-relay Y comprises also a home-signal retractivemagnet or back magnet L and a distantsignal retraetive magnet or backmagnet I. The home clearing front coils K and the home and distantclearing front coils J are arranged all in line with one another andwith the two home and distant clearing front coils J between the homeclearing front coils K, so that the latter occupy the extreme or outerpositions of the set of coils. The cores of the home clearing frontcoils K are secured in the extreme ends of a common back iron, such as47, which does not connect with the coilsJ, but is curved so as to passaround the cores of such home and distant clearing front coils. Thecores of the home and distant clearing front coils J have no fixed backiron,

but on the contrary present polar extremi-- ties at both ends of theirrespective coils. A home clearing relay-armature, which is not shown inthe diagram, isinterposedbe-= ends of the cores of all four coils J K ofthe home and distant clearing front magnet, so as to be attracted by allof them jointly, while being oppositely attracted by the homesignal backmagnet L. The home clearing relay-armature is unbiased-that is to say,it is provided with no retractive means or positioning means other thanthe attractiw forces of the magnets between, which it is interposedandit will therefore be moved in the direction of preponderating magneticattraction fromthe magnet on either side of the armature and will remainin the position effected by such movement until it is oppositely movedby an opposing preponderance of magnetic attraction from the magnet onthe opposing side of the armature. It is suitably connected with itscontact-finger f in such manner that when the armature moves toward itsfront coils J K the contactfinger f will be moved into position ofcontact with its contact-stop 9, while the opposite movement of thearmature will cause the contact-fingerf to move out of its position ofcontact with such stop.

A distant clearing relay-armature (not shown on the diagram) isinterposed between the home and distant clearing front magnet and. thedistant-signal retractive magnet or a back magnet I in a manner similarto that described with respect to the home clearing relayarmature,excepting that the distant clearing relay-armature is only subjected tothe magnetic attraction of the home and. distant clearing front coils Jof the home and distant clearing front magnet and. to the opposingattraction of the distant-signal back magnet I andis not influenced bythe magnetism of the home clearing front coils K. The distant clearingrelayarmature, like the home clearing relay-armature, is unbiased andmoves in response to preponderance of magnetic attraction from either ofthe magnets between which it is interposed. It is suitably connectedwith its contact-fingers a and 0, so that movement of the armaturetoward the front coils J moves the contact-linger 0 out of position ofcontact with its contact-stop I), while moving the contact-finger 0 intoposition of contact with, its contact-stop e, and vice versa. cores ofthe home and distant clearing front Each signaling apparatus comprises abatwry-switching d.evicesuch, for instance, as

that indicated in the diagram and including two pivotally-mountedcontact-levers, such as q and a, cooperative with an actuatingrod, suchas t, which is connected to the home-signal semaphore H, so as to movein one direction with the movement of the semaphore to clear positionand in the other directionwitli the movement of the semaphore to dangerposition. u is normally in position of contact with its -contact 'springU and out of position of coni tact with its contact-spring 54, while thecon- The contact-lever tact-lever gis normally out of position ofconmerely shifted farther from its position of contact with thecontact-spring s, and when the actuating-rod t is moved in the oppositedirection bythe movement of the home-signal semaphore to its dangerposition the contact-lever u is momentarily moved out of po- 'sition ofcontact with its contact-spring v and into positionof contact withitscontactspring 54, while the contact-lever g is simul taneously andmomentarily moved into contact with its contact-sprin g s. The parts areso arranged and positioned that when the home-signal semaphore hasCompletely finished-its movement to its danger position the actuatingfingers or projections of the actuating-rod t will have passed beyondpositionsof engagement with the ends of the contactlevers g and u, thuspermitting such levers to return to their normal positions, such returnbeing assured by any suitable retractive Ineansfor instance, by effortof gravity unbalanced with respect to the pivotal centers of thecontact-levers. Eachsignaling apparatus also comprises three additionalcontact-levers, such as w, 2, and 6, the first of which cooperates witha contact-stop to close the circuit of the home and distant clearingcoils F of the rear track-relay X, while the two contact-levers 2 and 6,together with their cooperating contact-stops, constitute apole-changing device for reversing the connection of the advancetrack-battery 9 to the advance end ofits track-circuit. The threecontact-levers w, 2, and 6 are all actuated by the movement of thehome-signal semaphore in such manner that when the semaphore goes toclear position the contact-levers are moved into contact with theirrespectively cooperating contact-stops m, 3, and 5, and

vance track-relay Y and the home and dis-,

tant clearing front coil J thereof, as well as the home-signal backcoils L and the distantsignal back coilsl of such relay, are energizedby the advance track-battery 9 through the following circuit: from onepole of the advance traclibatteryfor instance, the positive polethereofthrough a positive battery conductor 10 to a terminal of one ofthe home clearing front coils K, and also to a terminal of one of thehome and distant clearing front coils J, thence from thebattery-conductor 10 through both the front coils-K in series with eachother to the conductor 11, and likewise from'thebattery-conductor 10through both the front coils J in series with each other to theconductor 11, the coils J being in parallel with the coils K, and fromthe conductor: 11 through the two coils'of the home-signalback magnet Lin series with each other to and through the opposite or negativebattery conductor 15 leading back to the opposite or negative pole ofthe battery, and also from the conductor 11 normally around theresistance R by way of the contact-stop b and its cooperatingcontact-finger a normally in contact with the stop I), so as to form ashort circuit around the resistance R'to the coni ductor 12 and from theconductor 12 through the two coilsof the distant-signal back mag-- net Iin series with each other to the opposite battery-conductor 15, leadingbackto the opposite or negative pole of the battery, the last-mentionedbranch of the circuit leading 9 5' from the conductor 11' to thebattery-conductor 15,-and including the distant-signal back coils I,being in parallel with the firstmentioned branch leading from theconductor 11 to the battery-conductor 15, and inroot cluding thehome-signal back coils L. The back coils L and I normally preponderatein their magnetic attractions for their respective relay-armatures, sothat the contactfinger f' of the home clearing relay-armature n and thecontact-finger a of such distant clear-- 1 1o -ing relay-armature isnormally held incontact with its'contact-stop b, so as to nor' mallyclose the short circuiting path which has already been traced around theresist'- ance R. It will be'notedthat there is still 11 5 another branchof the circuit of the advance track-battery 9, which shall be designatedasthe track branch fOI track-circuit of that battery and which leadsfrom there-- sistance R andthe contact-finger a through the conductor 12and from the. conductor '12 normally through the contact-stop 7 andcon-- tact-lever 6 of thesemaphore-actuated polechanger and thencethrough the conductor 13 to the advance end of the outer orrighthandrail 1" of the railway-block B and fromthe right rail 7* to theleft rail Z of the block B'through various branches not indicated in thediagram of this particular track-circuit,

but which will later be mentioned and which 13 will be made clear bytracing their respectively-corresponding branches of the trackcircuit ofthe block B but normally from rail to rail only through the railway-tiesand through the ground, such branch through the ties and ground beingtermed the leakage branch of the traclecircuit, and from the left rail Zthrough the conductor 14, connected to the advance end thereof, andthence through the contact-lever 2 of the pole-changer and normally toand through its contact-stop 4 and thence through the negativebattery-wire 15 back to the negative p0 e of the advance track-battery9. It will be noted that the track branch of the circuit of the advancetrack-battery 9, or what may be briefly termed the track-circuit of theblock B, is in parallel with both the homesignal back coils L and thedistant-signal back coils I of the advance track-relay Y, but is inseries with both the home clearing front coils K and the home anddistant clearing front coils J of that relay, so that as the resistanceof the track branch or trackcircuit decreases it will have the effect ofdecreasing the current in the back coils L and I and increasing thecurrent in the front coils K and J, while increasing the current in thetrack-circuit, and of course an increase in the resistance of thetrack-circuit will have opposite effects upon all of the coils. However,the normal resistance of the track branch or track-circuit of theadvance trackbattery 9, which normal resistance is the resistance of itsleakage branch from rail to rail through the ground and ties is such aswill only permit passage of an amount of current insufficient to causethe front coils K and J of the advance track-relay to preponderate inattraction upon their relay-armatures, so that both relay-armatures willbe normally held in positions of nearest approach toward theirrespective back coils and by preponderance of attraction of such backcoils. It will also be noted that the normal connection of thetrack-rails of the railway-block with its advance track-battery throughthe semaphore-actuated polechanger is such that the battery-currentflows from the positive pole of the battery to the advance end of theright rail of the block and flows from the advance end of the left railof o. 5 line.

We may first assume that a railway train or vehicle is approaching alongthe railwayline from a point in rear of the block B and that it hasentered the block in rear of the block B. Such entrance of the traininto the block in rear of the block B efi'ects an actuation of theadvance track-relay at the advance end of the block in rear of the blockB, which advance track-relay corresponds to the advance track-relay Yand which actuation of such advance track-relay causes all the coils ofthe rear track-relay at the rear end of the block B and corresponding tothe rear track-relay X at the rear end of the block B to be connected tothe rails of the block B at the rear end thereof, so as to form aconductive path from rail to rail at the rear end of the block, and thusto increase the conductivity of its track-circuit sufliciently to Weakenthe relative strength or magnetic attraction of the home-signal backcoils L of the advance track-relay Y in a measure which shall cause thecombined attraction of the home-clearing front coils K and the home anddistant clearing front coils J of that relay to preponderate in theircombined. magnetic attraction upon the home clearin armature of thatrelay. The manner in which entrance of the train into the block in rearof the block B effects the foregoing actuation of the advancetrack-relay at the advance end of the block thus entered, so as to throwinto connection with the track-circuit of the block B the reartrack-relay at the rear end thereof, and thus to increase theconductivity of such track-circuit, will all be described later inconnection with the entrance of the train into the block B and theeffect thereof upon the advance and rear track-relays Y and X. Upon suchincrease in conductivity of the track-circuit of the block B and uponthe consequent preponderance of the magnetic attraction of the frontcoils K and J of the advance track-relay Y at the advance end. of theblock B, the home clearing armature of such advance track-relay isattracted. toward the front coils of the relay and is held. in itsposition of nearest approach to such front coils, so as to close andmaintain contact between its contact-finger f and cooperatingcontact-stop g. Such closure of contact between the contact-fingerfandits stop 9 places the home clearing coils E of the rear track-relay X inconnection with the rear end of the track-circuit of the block B throughthe following branch of such trackcircuit from the right rail r leadingnormally from the positive pole of the advance trackbattery 9 comprisedin the apparatus at the advance end of the block B through the conductor16, connected to the rear end of such right rail and leading to thecontact-stop g, thence through such contact-stop, its cooperatincontact-finger f, conductor 17, both of the ome clearing coils E of therear trackrelay X, conductor. 18, contact-spring 4'), its cooperatingsemaphoreactuatedl contactlever u normally in contact with the spring,and from the contact-lever u by Way of the conductor 19 to the rearendof. the left railof the block Bflwhichleft rail'leads back to thetrack-circuit and through the'home-clearing coils E of the reartrack-relay X by way of the'branch which hasv just been closed at, thecontacts f 9. Such home-clearing current enegizes the home clearingcoils E sufiiciently to cause them to attract the main armature of therear track relay X. Thereupon the main armature moves to its position ofnearest approachltothe magnets of the relay and closesits contacts m nand 0 19.

Although the closure of the foregoing branch of the track-circuit of theblock B through thehome clearing coils E of the rear track-relay X adds:somewhat, to the conductivity of the track-circuit, it .does notsufliciently increase the conductivity of; the

' track-circuit 'to cause the front coils K and J of the advancetrack-relay Y at theadvanceend of the block B to preponderate in.

their magnetic attraction upon either of the relay-armatures of thatadvance track-relay, so that the closing of the contacts f g-oftheadvance track-relay Y doesnot immediately-produce any movement oroperation of; any portion of the signaling apparatus lo cated at theadvancecnd of the block B Immediately upon closureof thecontacts 0 p thehome-signal semaphore-actuating magnet h is energized through thefollowing circuit: from one polefor instance thepositive pole-of thesemaphore-actuatingbattery 8 through thepositive battery-conductor 24,

semaphore-actuating magnet h, conductor 25, contact-stop p,contact-finger 0, and thence through the negative-battery conductor 26back to thefopposite or negative poleof the'battery 8. Immediately uponenergization of the home-signal-semaphore-actuating magnet h thehome-signal semaphore H commences its movement to clear position. Suchmovement of the home-signal sema.- phore to its clear position bringsthe contactlever to into contact with its cooperating contact-stop x andalso reverses the semaphoreactuated pole-changer so as to bringthe-contact-lever 2 thereof into contact with the contact-stop 3 in lieuof the contact-stop 4',While bringing the contact-lever 6- of thepolechanger into contactwith the contact-stop 5 in lieu of thecontact-stop 7. This reversal of; the semaphore-actuated pole-changer atthe advance end-of the block B brings the advance end of the right railinto connection with the negative pole of the advance trackbattery 9 inlieu of the positive pole thereof and brings the advance end of. theleft rail into connection with the positive pole of the advancetrack-battery 9 in lieu of its negative pole, the circuit of the advancetrackbattery 9 then leading through the track-circuit of the block B asfollows: from the posi tive pole of such advance track-battery 9 throughits positive battery-conductor 10, and thence through the home clearingfront coils K of the advance track-relay. Y and through the home anddistant clearing front coils J of'such relay in parallel with the coilsK, and from the front coils K J through conductor 11, and thence aroundthe resistance R by way of contact-stop b and itscooperatingcontact-fingera to the conductor 12, thence through theconductor 12'and the contactstop 3 and its cooperating contact-finger 2of 'the semaphore-actuated pole-changer,thence through conductor 14 tothe advance end of the left rail Z of the block B, thence rearwardlyalong such left rail to and throughithe coils of the rear track-relay atthe rear end of the block B and corresponding to the rear track-relay Xat the rear end of the block B and from such rear track-relay of theblock B to the rear end of the right rail 7* of such block, and thenceforwardly along such right rail to the advance end thereof and to andthrough the conductor 13, and thence through the contact-lever 6 and itscooperating contact-stop 5 of the semaphore-actuated polechanger, andfrom such contact-stop 5 throughthe opposite or negativebattery-conductor 15 and-back to the opposite or negativepole of theadvance track-battery 9.

Prior to the foregoing reversal of the semaphore-actuated pole-changerby the clearing movement ofthe home-signal semaphore H current flowedfrom the advance track-battery 9 through its entire track branch ortrack-circuit in home clearing direction cor responding. in directionand in results to the homeclearing current which is now flowing in theblock B and which has just effected the clearing of the home-signalsemaphore H and the reversal of its semaphore-actuated pole-changer; butnow, however, current gassingthrough the track-circuit of the blockwhich has just been traced, flows through the railsof such block andthrough the rear track-relay connected to the rear ends thereof in thedirection opposed to the home clearing direction of current which flowedin the track-circuit prior to the reversal of its polechanger. Thisreversed current in the rails and rear track-relay of the block B istermed the distant clearing current, because it effects the clearing ofthe distant-signal semaphore at the rear end of the block B in a manrroner which we are about to consider with reference to the clearing of thedistant-signal semaphore D at the rear end of the block B and when thetrain shall have entered the block B immediately in rear of suchdistantsignal semaphore D. The home-signal semaphore at the rear end ofthe block B was cleared prior to the clearing of the distantsignalsemaphore at that place, and when the train was present in the secondblock in rear of such signals and in a manner corresponding to theclearing of the homesignal semaphore H, which clearing operation hasjust been described as effected by presence of the train in the secondblock in rear of such home-signal semaphore H, which second block is theblock in rear of the block B. As the train now proceeds through theblock in rear of the block B and approaches the signals at the rear endof the block. B it is assumed that the engineer notes that both the homeand distant signals at the rear end of the block B are in their clearpositions indicating that the two blocks successively in advance of thesignals are clear. Upon noting such clearsignals the engineer mayproceed at full speed into the block B.

The exit of the train from the block first in rear of the block B,provided there is no other train in such first'rear block or in theblock second in rear of the block B, actuates the advance track-relay atthe advance end of such first rear block to open the two rear branchesof the track-circuit of the block B, which lead through the homeclearing coils and through the home and distant clearing coils of itsrear track-relay, such opening of such branch circuits beingaccomplished in a manner which will shortly be described with referenceto the exit of the train from the block B and the effect thereof uponits advance track-relay Y and upon the rear trackrelay X, controlled bysuch advance trackrelay. Such opening of the rear branches of thetrack-circuit of the block B is not effected, however, until therailway-train or the advance cars or wheel-trucks thereof have enteredthe rear end of the block B, and when the train or the advance endthereof has entered the block B its wheels and axles constitute a shortcircuit of great conductivity from rail to rail thereof, so that thetotal conductance of the track branch or track-circuit of the advancetrack-battery 9 is greatly increased, or, in reciprocal terms, theresistance thereof is greatly decreased, and with the result that stillmore current is shunted from the back coils L and I of the advancetrackrelay Y, while the current in its front coils K and J iscorrespondingly increased, and in consequence the relative attractiveforces exerted by the front coils upon their respective armatures aregreatly increased. Such increase in the relative forces of attractioneX- erted by the front coils can only affect the home clearingrelay-armature to draw it more strongly toward such front coils, so asto more firmly press its contact-fmger f against its cooperatingcontact-stop 9; but the distant clearing relay-armature, which is soadjusted that up to the present instant it has not been attracted by thehome and distant clearing front coils J, now moves to its position ofnearest approach toward such front coils, and thereby breaks contactbetween its contact-finger a and cooperating stop I) and makes contactbetween its contact-finger c and cooperating stop 0. The breaking ofcontacts a Z) opens the short-circuiting shunt around the resistance R,and thereby throws this resistance in series with the track branch ortrack-circuit of the advance track-battery 9 and also in series with thedistant-signal back coils I, which are in parallel with such trackbranch; but such breaking of contacts a b throws the resist ance B intoparallel with the home-signal back coils L, one result being to reducethe current flowing through the track branch or track-circuit, and thusavoid excessive intensity of current due to the short-circuiting effectof the railway-train as it approaches the front end of the block B andgradually cuts out more and more of the rail length and rail resistanceleading through the track-circuit to such short-circuiting train. At thesame time the introduction of the resistance R, together with theprogressive reduction of rail resistance in the track-circuit as thetrain advances, still further reduces the intensity of current in thedistant-signal back coils I but such further reduction of current in thedistant-signal back coils can only have the effect of still furtherweakening their retractive effort upon the distant clearingrelayarmature, so as to permit the armature to be drawn still moreforcibly toward its front coils J. The introduction of the resistance Ris, however, opposite in its effect upon the home-signal back coils L,because such resistance is introduced in parallel with the home-signalback coils and in series with all the other circuit branches which arein parallel with the home-signal back coils, and must therefore increasethe joint resistance of all such branches -or paths parallel with thehome-signal back coils, so as to reduce their total or jointconductance, which tends to shunt current around'or take current fromthe home-signal back coils and by so reducing such conductance to causemore current to flow through the home-signal back coils L. At the sametime, since the resistance R is introduced in the circuit of the advancetrackbattery 9 in series with the front coils K J the current in thesefront coils will be somewhat reduced by such introduction of theresistance, the whole result as regards the attractive forces of thefront coils K J relative to attractive force of the home-signal back 66by attraction of the main armature of the coils isnot, however, 7

duced sufiiciently to permit the attraction of i the horne-signalbackcoils L to preponderate a ain coils Lbeing to reduce the magneticattraction of the front coilsupon the home clearing relay-armature. Therelative attractive force of the combined front at this instant reuponthe home clearing relay-armature and crease in the retract the same. Theeffect of theintroduction of't'he resistance R'is rather merely to,

partially compensate or neutralize an ins I preponderance of-mag'neticattraction of the frontcoils J K over and above the critical actuativepreponderance thereof,

whichwas required to draw the home-clear-i ing lrelayarmature towardthem and which increase in front-coil preponderance now eX- istsbecausef of reduction in the tween the front coils and'the home'clearingair-gap 'berelay 7 armature. occurring. simultaneously with I acprresponding increase the air-gap between such armature and its backcoilsL, such [changes in the air-gaps being Q due tomovement of thearmature toward its front back coils and which coils and awayirom itsincrease'in front-coilv preponderance exists further because of theconsiderable reduction in theresistance of the. track branch of the'circuitin serieswith the front coils and in para'llel'with thehome-signal back coils. Theobject ofthus partially neutralizing the preonderance ofmagnetic attractionof the out coilsK is to facilitateretraction of the home-clearing relay-armature by its back. 'coils Lwhen the latter shall be required to. again prepjonderate and retractthe home I clearing relay-armature to its'normal posie p position ofcontact'with the sto 1 and from the contact lever'w ductor 21', home anddistant track-relay coils F, conductor .able as follows: from therightrail r of the block B through the con ducto r' 16; connectedthereto, and thence tion upon exit of the train from-theblockB.

The closing of the contactsic 6, due to at traction of the distantclearing relay armature by thehome and through contact-stop, 6, itscooperating-com tact-finger c, conductor 20, con'tactestop or, itscooperating semaphore a'ctuated contact leverw, which has already beenmoved into movementof the home-signal semaphore H,

' through conclearing rear 22; contactstop vn, its cooperatingcontact-finger m-,. already'brought into contactwith the stop atrear'track-relay X', and from thecontact-fin ger m through conductor 18,contact-spring '1), its semaphore-actuated contact-lever w,

and the conductor 19 to the-rear end of the p as by clearingpreponderance of leftrail ofthe block Current is still v ing through therails of the block B in home Y clearing direction, andit is thehomeclearing direction of current which now flows through v the home anddistant'clearingicoils F of the rear' track-relay, and this homeclearing 'direction of current in such home and distant clearing coils Fonly forces their pivoted'po larizedarmature j'more firmly out ofor awayfrom itsp'osition of contact with its cooperating contact stops k andi.Theparall'el' or multiple introduction of'thehome and dis tant clearingrear coilsF reduces the joint resistance of all the branches of thetrack-' circuit of the block Bi or, in otherword's; increases the totalconductance ofsuch track- ,circuit in such adegre'e as to initiallyactuate the advance track-relay Y connected to the advance end of theblock suchiniti'al actuation of the advance: track-relay Y is effectedin the'gmanner which has already. ,been described with reference to thecorresponding initial actuation of" the advance track-relay Y,such'initial actuation of the advance track-relay'iY consisting in themovement of its home clearing relay-arma'= ture away fromitshome-silgnal back coils-L I and toward its front coils v suchmovementbeing dueto prep onderance of magnetic attraction of such frontcoils'upon. the home clearing armature and being caused by'the increaseinrtota'l conductance'of the track-circuit of the block B Suchattraction of thehome clearing relay-armature of the ad:

.vance track-relay Y brings 'itsaconta'ctfin "ger f into'contact withits contact-stopgi and thereby introduces the home clearing coils Eof-the rear track-relay X 'int'he rear end of the track-circuit"of theblock B 'whereupon the block'B beingiclear of trains; (960., the homeclearing coils 'E of its rear track-relay X are energized and. attractthe main armature of such relay, and'thus' close their contacts m n and0 p a'llin 'theQ'man- .ner which has already been described with respectto the corresponding operation ofthe relays Yaand; X att'he advance endof the block B'-and'fat the:rearend of the block B Upon closure of thecontacts 0 p whichare included in-r'the localf circuit'of the home"semaphore-actuating magnet 72 at tthe"rear T'TO end of the block B suchsemaphore-actuat ing magnet is energized-and causes its home- 'signa'l'semaphore' H to move to clear position, thus reversing the positions ofthe"con= tact-levers 2 and 6 of'itssemaphore actu Y ated pole-changerand causing a"reversalf-'of the home clearing current through therails'of the block B all inthe'mann-er whichhas already been described withrespect 'to the pole-changera-t the rear end-of the 'bl'ock B As thehome clearing current in the rails of the block B is reversed there isof course amoa 5 a corresponding operation of the home-signal semaphoreII and its semaphoreactuate'd mentary cessation of current, during whichthe rear traclcrelay X of such block may release its main armature andpermit the same to be momentarily retracted, so as to momentarily openat its contacts m n and o 19, respectively, the distant clearing rearbranch of the track-circuit of the block B and the local circuit of thehome-semaphoreactuating magnet h, controlling the home-signal semaphoreH at the rear end of such block. The consequent momentary denergizationof the home-semaphore-actuating magnet it does not, however, result inmovingits home-signal semaphore H to danger position, since the durationof such deenergization is less than the period of retention of thesignal. Immediately after the foregoing momentary cessation of currentin the rails of the block B as the home clearing current therein isreversed the current is reestablished in reversed or distant clearingdirection, and the main armature of the rear track-relay X, beingresponsive to current in either direction in the home clearing coils Eof the relay, is reattracted by distant clearing current in such coils,so as to reclose at its contacts at n and 0 1), respectively, thedistant clearing rear branch of the traclccircuit of the block B and thelocal circuit of the home-semaphoreactuating magnet h at the rear end ofsuch block. Now that such distant clearing rear branch of thetrack-circuit of the block B is reclosed, so as to again include in suchtrackcircuit its home, and distant clearing rear coils F, distantclearing current will pass through such home and distant clearing coilsand their cores will be magnetized with a distant clearing olarityorpolarity opposite to that produced by the home clearing current, so thatsuch home and distant clearing coils F will cause theirpiv0tally-mounted polarized armature j to swing into its position ofcontact with its cooperating contact-stops 7c and i, thus closing thelocal circuit of the distant-serhaphore-actuating magnet d, which localcircuit is traceable as follows: from one ole of the semaphore-actuatingbattery 8 or instance, the positive pole thereof through the positivebattery-conductor 24 distant-semaphore-actuating magnet (1, conductor28, contact-stop i, polarized armature j, contact-stop k, and negativebatteryconductor 26, back to the opposite or negative pole of thebattery. The distant-semaphore-actuating magnet d is energized by suchclosure of its local circuit and immediately causesits distant-signalsemaphore D to move to clear position, thus indicating theclear'condition of the block B second in advance of such distant-signalsemaphore D.

Now proceeding onward through the block B, the train comes uponclear-signals at the advance end thereof and continues into the -116Xl3block B leaving the block B behind.

When the train has entered the block B its wheels and axlesshort-circuit the rails there* of and effect the second operation of theadvance track-relay Y connected to the rails of the block at the advanceend thereof, all in the manner already described with reference to thesecond or distant clearing operation of the advance track-relay Y at theadvance end of the block B and when the train had entered such block B.This second or distant clearing operation of the advance track' relay Yconnects the home and distant clearing coils F of the rear track-relay Xin the rear end of the track-circuit of the block B and in parallel withthe home clearing coils E of such rear track-relay. Thereupon theadvance track-relay at the advance end of the block B is actuated toclear the home-signal semaphore at the advance end of such block,providing, of course, that the block in advance of such home signal isclear. Such clearing of the home signal at the advance end of the blockB effects a reversal of the semaphore-actuated pole-changer at theadvance end of such block and a consequent change of home clearingcurrent in such. block to distant clearing current therein, whichactuates the polarized armature j of the rear traclcrelay m at the rearend of such block-and thereby closes the local circuit of thedistant-semaphore-actuating magnet (Z and clears the distant-signalsemaphore D", all in the manner which has been hereinbefore describedrelative to the similar operations occurring, respectively, one blo ckin rear. Thus the train proceeds along the railwayline, and, assumingthat it at no time approaches another train in either of the two blockssuccessively in advance, it continues to cause the signals to clear asit approaches 'them, each home-signal semaphore being cleared when thetrain has entered the block second in rear thereof, and eachdistant-signal semaphore being clearedwhen the train has entered theblock immediately in rear thereof.

When the trainleaves the blockB, such exit of the train opens the.short-circuit which has been maintained from rail to rail of such blockby the wheels and axles of the train, and providing there is no othertrain present in such block nor in the block in rear thereof theconductance of the track-circuit of the block B is reduced below thevalue of the first actuative conductance of such track-circuit or itsconductance which was necessary to effect the initial operation of itsadvance track-relay Y, which initial operation consisted in theattraction of its home clearing relay-armature toward the front magnetof such relay, and obviously this reduced eonductance of thetrack-circuit which is below such first actuative conductance must bestill farther below the second actuative conductance which was necessaryin order to effeet the second operation of the advance "its distant]nearing;- relay-a1 the. front fcoils fof such relay; "because as we,havefa'lready seien,- such; second-slctuatiye con diictanc'eg ofthejtrackcircuit' must be'1 eve'n' consisting iat'i re "towardhigherithah theifirst acti'iative conductance v conductance of the'trackEcircnitiuponeiiit Of i the train from the blockJBwillilnder'ajllcondi fFmeg B :a t a io 5 Qfthereof; Therefore ,suehredujction of the tiOn's} be s ifiicient to restore' preponderancei bck; magin d -and notwithstanding gthefact j wit ' tractfth' d e "-k overand above} ,req rires' that the rnagnet J P 'd ii an im yfiw dair-gainbetweensnch' aimELti1reF and1-its hack" -W 1- liTheifactthatthefjprep'ongieran eof ea-ring} ontilcoils'J distantlf armature has'already be nppn overs n; l

siderft bly increased v I l calaetuatiye preponderance} 11 tant lean narm'atn h; c t eia wja iv n-brt *iKJ ont coils-J.

H armaturefhas sim larly.increased by! ,moy'ementf ofl arma tiire'toward the lfrontfcoilsl and s" critical;ajctiiative yaliie lll-jofftrai kE'ci'rcuit con ductancegn'e es effect retractionfof the gfl y;armatii're bywits ,back

e t, l bexd i id l ly' th n t e criticalyalil e df ithe 'fijrst a'ctuativeecondirctk circiiit which-efiectsfthe'a earingi rela at-traction 5finfthe distant si'gnali preponderanceloffthehcinei anddisr fle e i:vtan-t rcIearmgQarmatur'e cause esq hgrnratnre, toward" cu ri ggsimultaneously 7.

eas inf-the .f

tion' of 1its" distant c learing' relay armature andy after "attractionof its home clearing relay armat iretoward the front coils of: the relay2 effects a' preliminary increase of-Tesistthe efie'ct of a.preliminaryred'uction of its con- Jthe "air: a'p "increase; inpreponderance of the their} home clearing armature.

\ c c c Since both thej'home clearing and distant clearing relaytowardtheir; respective back magnets when Ilthe"trainmakes,its exit fromtheeblock B un- Irelay-a'rine l re;which distant clearingrelayarmafture' at the endofits retractive move contacts (t-b sothat. heresistance R will be Qre'tractiyej ,rnoy'e'ment of ,the home clearingrelay arma'ture juntil suchretractive movement theeof' has beencompleted.

' e may now go' back. tothe point here further results of theprogressive movement deredI As soon as; the forward. part of the 5batteryigtl rearwarcllyalong'the'rails of the.

and thereby; ole rives these rear re: "of current lay coils" tactmakingpositions, and'the armatures are I 1m j trol, whereupon the, home i anddistan At the" same time inciance "in series ith'jthe-track{circuit andhas yfront colls' of the advancetrack-relay Yupon I arniatires-ofthe'fadvance;trackfrelay Y start simultan ousl ntheirretractivemovements v der the {conditions {which have already beenv mentioned;-it isfapparent that the retractiv'e swing ormoyement of thehome clearing rel'ay- "armattir'e'mayvbe' so adjustedfand determinedthat retr ective Imovement Will lo e comipl'etednot'later than-thecompletion of the v movement ;of the distant clearing ment shortcirciiits"theIresistance R atthe injcircuita'nd. will be effective ininsuring the the r- 1n iind rconsiderationwas just about of thetraii'l'. vlvhichj as yet have-not been cone 'dnc'tance' tending tocompensate .or neu tralize- I to'enter'gthe rear end of the block B andfrom' ftheblockaB' inrearthereo'f and may consider V trainenter's theblockfBi'andits heels and iaxle'sestablisha shorticircuit across therails thereof, both theghome clearing relay-coils .E

j and home" and distant clearing relayecoils Fof the rearitrack-relay Xof such block are deenergized'; becau'sefthe shortwcircuit made,theitrain take'ssubstantially'allthecurrent transmittedffrorn, theadvance track-11'0 6 i I immediately" upon I: i such ieenergizatim ofthegcoils of the rear 7 track}relay,X both'itsfmain armature and itsp'olariZedermature f'ylare' released'rrom' the -ma'gneticwforeeswhichgret'ai-n thern in; con clearingr-j i i I cliatelyretracted;:soastofbreakfthelo- V. v ca ir cuitso fthehome semaphore-actuating 1magnet h and the distantrse'mapl1oreactuat- I ing magnet 11d, which theyrespectively coni t signal semaphores H and 'D immediately goto their.i-ds e p t ffdentally, the droppingjor; retraction ofithe mainarmaturereopens' at/its contacts m n v {the rear; branch of; the trackecircuit B:Which" includes'l the home and; distant. coils F of the,reartrackrelayofsuch block; As thehomee.

signal semaphore H goes to its danger position its semaphore-actuatedpole-changer is reversed, so as to again reverse direction of current inthe rails'of the block B, and thereby reestablish in such rails the homeclearing direction of current; but since the rails of the block B arestill short-circuited by the rear portion of the train, which has notyet left the block B, this home clearing direction of current wouldproduce no immediate effect upon the apparatus at the rear end of theblock'B even though the home clearing relaycoils or boththe homeclearing and the home and distant clearing coils of the rear trackrelayof such block were placed in circuit by the approach of another traintowardthe block B and from the rear thereof in the manner which hasalready been described with respect to the initial approach of the train.the progress of which we are considering.

The same danger movement of the home-signal semaphore H at the rear endof the block .B reopens at still another point the rear branch of thetrack-circuit of the block B which includes the home and distantclearing coils F, this second point at which such branch is reopenedbeing at the semaphoreactuated contact-lever w and its cooperatingcontact-stop 0c. The same danger movement of the home-si nal semaphore Hat the rear end of the bloc B operates the semaphoreactuatedcontact-levers q and u, permanently connected, respectively, with theright and left rails r and Z of the block B by means of the conductors16 and 19, leading to the rear end of such rails, respectively, so as tofirst break the circuit of the home clearing relay-coils'E- at thecontact between the semaphore-actuated lever u and its contactspring '0and then to bring the right and left rails, respectively, intoconnection with the negative and positive poles, respectively, of thelocal semaphore-actuating battery 8, or what will be hereinafterdesignated also as the relay-restoring battery, such connection of therelay-restoring battery 8 with the rear ends of the rails being madethrough a branch of their track-circuit traceable as follows: from therear end of the right rail 1" of the block B through connecting-wire 16,semaphore-actuated contact-lever q, its cooperating contact-spring s,and conductor 27 to the negative pole of the relay-restoring battery 8,and thence through such battery to the positive pole thereof, and thencethrough conductor 23, contact-spring 54, its cooperatingsemaphore-actuated contact-lever a, and thence through conductor 19 tothe rear end of the left rail Z of the block B As has already beenexplained, the semaphore-actuated contact-levers q and u are onlybrought momentarily into contact with their respective cooperatingcontact-springs s and 54 during the movement of the homesignal semaphoreH to its danger position, so

s'fAii that current flows from the relay-restoring battery 8 onlymomentarily through the branch of the track-circuit which has just beentraced from rail to rail and through the shor tcircuiting wheels andaxles of the front portion of the train at this time making its entranceupon the block B and of course the short-circuiting effect of suchwheels and axles prevents such momentary current from being transmittedforwardly along the block B thereby affecting or actuating the advancetrack-relay Y at the advance end of such block in the manner in whichsuch advance track-relay Y should and would be actuated by suchmomentary or relay-restoring current if the train were to leave theblock B by a siding or by a branch railwayline in lieu of passing out ofthe block B into the block B When the home-signal semaphore H hasreached its danger position, the actuating-rod t of the pair ofsemaphore-actuated contact-leversq and a has passed beyond its positionof engagement with such levers, and the latter have been retracted frompositions of contact with their respective contact-springs s and 54,while such retractive movement of the contact-lever a has moved it intocontact with its cooperating contact-spring 1), so as to reestablish atsuch point the rear branch of the traclecircuit of the block B includingthe home clearing coils E of its rear tr ack-relay. The train nowproceeds farther into the block B until it has left the block B in rearthereof, whereupon the short-circuiting effect of the train is removedfrom the block B and the back coils L and I of its advance track-relay Yretract their home clearing and distant clearin relay-armatures,respectively, as has )een already pointed out, thereby opening at thecontacts f g, controlled by the home clearing relay-armature, the rearbranch of the trackcircuit of the block B which includes the homeclearing coils E of its rear track-relay, and still further opening atthe contacts c a,

controlled by the distant clearing relay-armature, the rear branch ofsuch track-circuit, which includes the home and distant clearingrelay-coils F of such rear track-relay and which latter branch wasalready open at the semaphore-actuated contacts to a; and at thecontacts m a, controlled by the main armature of such rear track-relayX. Thus the train has passed from the block B into the block B and in sopassing has restored both the home and the distant signal semaphores Hand D to their normal danger conditions or positions, while at the sametime restoring the armatures of both the rear track-relay and theadvance track-relay Y to their normal or retracted positions ready to beagain actuated by the approach of another train and all in the mannerhereinbefore set forth. Should the train leave a block of the system-forinstance, the block B-by way of a siding or branch line 1 and iIi lieuof *out into the next blockysuch as B "vance, the coils of there'ar'track-relay, such.

sea-411 in ad;

asXQ'of such advance block would of course; not be d'energized by theshort-circuiting ef-i fect ofthe train; which effect has been describedas resulting from entrance of-the train upon such Iadvance block; butboth the;

home-clearing and the: distant clearing ar-f matures of the advancetrack-relay,

such as; Y} of the block from whichthe train would, make eXitunder theseconditions w'ould be:

} retractedi'in the manner which has already- I controlled by sucharmature, the rear branch i been described as resultingfrom eXit of a;train from the block. The retraction of the home clearing'relay-armaturethus effected. would of coursebreak-at the contacts if 9,

' of'dthe track-circuitof the advance block B including its rear'horneclearing coils E while; the retraction of the distant clearing -relay:armature would simultaneously break at the contacts e controlledthereby, the rear? branch of such track-circuit including its 'aringrelay-coils home and distant cle I 7 Upon such breaking of the branchesincludmg the coils of the rear track-relayX at the;

rear end'of the block B such rear track-re 'lay will of course bedenergized and will recourse, that the home clearing relay-armaturelease bothits armatures, all the results of suchdenergization andrelease being the; same as the resultsfollowing suchdener gization andrelease when produced in the manner already described by theshort-circuiting effect of the entrance of the train into the block Bexcepting the result of the 1110-;

mentary flow'of relay-restoring current from the relay-restoring battery8 and through the v trails of the block B which momentary relayof suchadvance track-relay has been attracted toward its front coils, so as toclear the homesignal at the advance end of the block B in the'mannerwhich has already been described as resulting from presence of a trainin the; I second block in rear of suchhorne signals,

If the home signal semaphore H at the advance endof the block B has beenthus! cleared, its semaphore-actuated pole-changer will of course havebeen'reversed, so that 131165 contact-levers 2 and 6? thereof will be incontact, respectively, contact-stops 3 and 5l,'so as tosend current overthe track-circuit in distant clearing direction from the advancetrack-battery 9 controlled by such pole-changer. Under these conditionsthe relay-restoring battery 8 at the rear end of the block B will bemo-' r s a thence through conductor l2 with their cooperating mnairnyconnected a andwili momentarily be effective throughout the followingcircuit: from the positivepole ofsuch relay'-restor= ing battery 8through the conductor 23,"con-g tact-spring 54:, semaphore-actuatedcontact-7e lever a, conductor 19, left rail Z of the block B conductor14", connected to the advance end ofsuch left rail, semaphore-actuatedcontact-lever 2 its'cooperating contact-stop3 conductor 12 to theconductor 15 't-hrou'gh three-parallelbranches, as follows one branchleading. from the conductor. 12 through'the coils I ofthe distant-signalback magnet 'and to 'ithejconductor 15*, the 'secondbranch 8oleadingffrom the conductor12 around the resistance R byway ofcontact-fingerct and" its cooperating contactstop 5 and thence'throughconductor-11 and-coils L of the home-signal back magnet to 'the'8 5conductor 15 and the third: branch also leading from the conductor 12around the resistance R by way of the contactsa b and to the conductor11 but from such conductor branching through the front coils K J of dthe advance track-relay Y such front'coil s- K and J 2 being: of coursein parallel with each other, and from such front coils through the Yconductor 10 to the positive pole of the advance track-battery 9 andthence through 5 such battery to the conductor 15 wherein the threeforegoing parallelbranches are reunited, it'beingnoted that inthis-third branch ofthe circuitof the relay-restoring battery 8 thedirection of the electromotive i force of the advancetrack-battery 9 is01. posed to the direction o f the electromotive force of suchrelayrestoring battery"8-, and from such rejuncture of the three foregoingparallel branches the circuitcontinues through I o 5 the conductor 15and from such conductor through vthe contact-stop 5*, its cooperatingsemaphore-actuated contact-lever '6 1 conductor 13 connected to theadvance'en'd of the right rail 1" of the block B thence'through {1 1osuch right rail conductor :16, connected to the rear end thereof,semaphore-actuated contact-lever q, its cooperating contactspring 3, andconductor 27. back to the negative pole of therelay-restoring battery 8.It'u5.

will be noted that although the relay-restoring-battery 8 thusmomentarily connected in the rear'endof the track-circuit-ofthe block B?and the advance track-battery 9*, connected to the advance end of suchtrack cir- 12o cui t, are opposed to each other in the gdirection inwhich they tend to induce flow of ourrentthrough the front coils K J 2of the trackrelay Y at the advance end of such trackcircuit suchbatteries commonly tend to in- I 2 5 duce flow of current in onedirection through the back coils L and 1 of such advance track-relay, sothat although the effects of the tWo batteries are opposed and tend toneutralize each other as regards 'energization of the front coils of theadvance track-relay they are, on the contrary, united or coordi- ,natein energizing the back coils L and 1 thereof, the result being that thedistant-sigback coils L are likewise caused to strongly preponderate intheir magnetic attraction upon their home clearing relay-armature, so asto retract the same positively. Of course under ordinary conditionsthese home-signal back coils L would be caused to preponder ate upon andto retract their home clearing relay-armature merely by reduction inconductance of the track-circuit of the block B due to opening both itsrear branches including its rear home clearing coils E and its rear homeand distant clearing coils F, such branches having been opened, asalready stated, by retraction of the armatures at the advancetrack-relay Y upon exit of the train from the block B onto a siding orbranch; but should extreme wet-weather conditions prevail, so as togreatly increase the conductance of the leakage branch of thetrackcircuit, and thereby tend to prevent proper retraction of the homeclearin relay-armature of the advance track-relay? by its back coils Lthen the momentary flow of relayrestoring current from therelay-restoring battery 8 would be effective in the manner which hasjust been described to insure the proper retraction of suchhome-clearing relay-armature.

It will be noted that should the train under consideration approachanother train occupying any block in advance of such train the progressof which we have been considering the wheels and axles of such advancetrain wouldshort-circuit the rails of the block entered thereby andwould thus effectually prevent transmission of signal-clearing currentthrough such block from its advance trackbattery to its rearsignal-clearing track-relay, such as X, thereby eifectually preventingenergization of either the home clearing coils or the home and distantclearing coils of such rear track-relay when such coils are connected inthe rear end of the track-circuit of such block and byattraction of thehome clearing relay-armature or both the home clearing and distantclearing relay-armatures of the advance track-relay, such as Y, at theadvance end of the block in rear of such block entered by the advancetrain. Such prevention of energization of the coils of the reartrack-relay of the block entered by such advancin train will of courseeflectually prevent c earin of either the home-signal or distant-signalsemaphore at the rear end of such block, while such prevention ofclearing of such home-signal semaphore will of course prevent reversalof its semaphore-actuated pole-changer, thus preventing the sending of adistant clearing current to the si naling apparatus atthe rear end ofthe bloc in rear of the block entered by such advance train, or if atrain from a siding or branch suddenly enters a block of the systemafter the home signal or both the home and distant si nals at the rearend of such block have been cleared by the advance of another traintoward them it is of course obvious that either or both of such signalswill immediately go to their danger positions because of completedeenergization of all the coils of the track-relay at the rear end ofthe block thus entered and consequent opening of the circuits of thesemaphore-actuating magnets controlled by such relay, suchdeenergization of the rear relay-coils being caused by short-circuitmgeffect of the entering train, which effectually prevents transmission ofsignal-clearing current from the advance to the rear end of the blockwhich the train enters. If only the home-signal semaphore is cleared atthe time the train thus enters the block from a siding or branch and ifthe clearing of such homesignal semaphore has already effected the re:versal of signal clearing current in the block in rear thereof, so as toclear the distant-signal semaphore at the rear end of such rear block,such home-signal semaphore at the rear end of the block thus enteredwill of course immediately go to danger position, so as to reverse itssemaphore-actuated polechanger and reestablish home clearing current inthe track-circuit of the block inr ear thereof, so as to retract thedistant clearing relay-armature or polarized armature, such as j,comprised in the track-relay at the rear end of such rear block, andthereby open the local circuit of the distant semaphore-actuatingmagnet, such as d, in order to restore such rear distant-signalsemaphore to its danger position.

It will be noted that when the home and distant clearing coils, such asF, of one of the rear track-relays, such as X, are connected in thetrack-circuit of the block in advance thereof and in parallel with thehome clearing coils, such as E, and by attraction of the distantclearing relay-armature of the advance track-relay, such as Y, of theblock in rear of such rear track-relay and due to entrance of a trainupon such rear block such introduction of the home and distant clearingcoils, such as F, not only serves to reduce the resistance or increasethe conductance of their advance track-circuit in order to actuate theadvance traclcrelay, such as Y, at the advance end of suchtrack-circuit, and thereby establish in such track-circuit a distantclearing current to energize such home and distant clearing-coils F witha polarity which shall attract their polarized armature and clear theirdistant signal D, but such home and distant clearing-coils F when theyare currenti-from'suc'hhomeclearing coilswhen-" the home.- andfldistantclearingfcoilsziare con z hected parallel 'th61Wltll',,tOi take" partof,

ithe u'rrent from thetracki i fcuit sueh-weak? i I iIl g -1 Qfflih 6:attractive force ,of the heme. clearing; coils isTc mpensatedby-estab'li'sha, and consequent attractive? y subtraction of efand'distant clearin coils,

whirebygthe total? attractive force e ective t upon, the mainarmature ofthe ear track TeQ ,fiiGt'u-ate'the'signalingapparatus at! tthe-advancefend thereof '9 1 em d m nt mytim s wmed=- g-:.2 isa1I110rmal-danger,-:home; fi a w yi e ksigi al g'ls'ys i general.features to the systemy l in orderl .isimilar in; r :diagrammed-Hi' i ifrominvariouspart I I f set forth-:in-afdescript ts ati nj {I p thesyste fof lfig'g 2g'those" 3. r if gsameiascorrespond i 1 in theis'ystemf-of-i Fig .Flg; but' -differin thereif f"W 1 0W an wingdejscription of 1 r a tureaotsuch system hen a and thosejfelements v Ii'andfeature'siofthesystem"ofiFig 2 whichiare :7 I sosimilar to,corresp'oi dirig elements; and'fea- 1 .tures of; the system. of; 1 :.that theirs'ftruc f '1 or Figijlif a be assumed-that} theflr e sistance's ofcFig;11- are constantly short-c'iref b quipped 1 lay i t i y em. at ationr'donot em-pl heir "co operation in-the system are the? foregoing, i deserill notybe' set forthini detail;

blocks: dfiagrar'nmed in Fig being simi 1Iisulated irom"teach otheralsobe ay-blocks B end's of; the; traekqcircuits of their respectiveblocks are-the} same a'S the advance track-re lays I o'f-the system ofFigg 1 eri ceptin'giin' the following particulars: The advanceftrackereresistances 'suchgasfiR gate- 11 g o a. maintaining their; confimon.rfnain armatilre'fimitsfpdsitionof attraction so that although, themagnetic at- Qtraction ofthe home gclear'in 'coilsjupon such i a mainarmature'i's weakened of r tsstructure and? emerits; andifea reobviouslythe I feleiijients vor features;

' hi'ch are normallygiltraversed railway-tra ns and-. similartoqthej'threefrailtem, .itmay-betaken asan example. with ralway.signalingfiappara} i ty to the adj acentxends give, iblocks."advance 1, respectively,

and g." con truction; i-operati'on; and in the r; lectr' clgcOnnec'tiOns .to'; the advance" -;pre e t underconsiderg iwith 1 theadvance trackrelays.- a'tur e,' the {advance 3 track-relays nstructure,connectiona and-opi ,eratlon the'samefas theJadvancetrack-relays;

u; also assist" the ijcuited, and? since these resistancesgare dis-"mused-withi the system of' Fig. 2 the (ad- Vancetrack-relays-thereof'also dispensc-wlth the IcOntactS; suchase b ofFig.'1 which are therein employed to control such resistances. Theadvancetrack-relays, such as Y of Fig. "2;;a'ctuate 'their;home-clearingarmatures in the'mannerwhichhas already been describedwithreference to the advance track-relays of th'ejsystemof;-Fig.j1,and,- as in the case of I-Figil,thejadvance'tra'ck relays inattracting V I suchhom'e' clearingrelay armatures toward their. frontcoils bring the home clearing conftact-fingers, 'such a s" f thereof,into contact -,with 7 their cooperating home clearingcontact-stopsysuchas 9; but although the operation 'ofjthe' distantclearing relay-armatures "oflthe advancejtrack-relays of-the system of,I Fig; 2;;is electrically-and magnetically ,the I distant "clearingarmatures of the-advance track-relays of Fig.1 the present instance vthese dis'tantclearihg. rela'y-arrhatures when attractedtowarditheirifront coils move their distant, clearing contact-fingers,such as 0 corresponding to the'contacefingers such as z c of Fig. l',ont ofcontact-making; positions 7 'sameas the corresponding operationofthe "with 1 their cooperating 1 distant clearing jcontactstopsfsuch asecorresponding to the contact-stops such asc of Fig. 1, in lieu offmov'ing'gsuchg contact-fingers: into contact with i such f distantclearing stops. when the- .distant clearingarmaturcs are attractedtowardfth'eir front coils li,Suchgattraction of the distantclearingarmature of the advance track-relays also moves theircontact-fingers, :such-[as *c ,--into'-positions of contact with theirrespective contaot stops, such as and [for a purposewhioh willhereinafter be develo ed J Psince the apparatus at thefadvance end of Ythe 'block- B is characteristic of apparatus 1 correspondingly" locatedthroughout t. e SYS- {The s stembf'Fi 2 comprises semipolar- [ized rear'trackrelayaj such as X including i homefclearingcoils'E and home anddistant clearing coils F, organizedtogether; and with a common "mainarmature .and a 'pivotallyinounted, polarized armature j, such coils andarmatureswbeingorganized and operating and cooperating all in the-mannerhereinbefore 'set/ forth'in the I description of the semipolarized reartrack-relays of the system of Fig. 1;

1 butthe rear track-relays of Fig. 2 difier from thos fFig.-1;in thatthey compriseback v magnets; suchas the back magnet G of the nserlted inthe'adv'anceends? "rear track-relay X which back magnet 'is disposed-inattractive proximity to the main homeyand distant clearing coils Fthereof,

whichmaygnow be; termed collectively the tion toitsback c'oilsThisdisposition of 1"front" coils jofthe relay in contradistincstops 3?and 42. nets are normally deenergized and their ar-- the back magnetmakes its attraction upon the main armature opposed to the attractionexerted thereupon by the front coils E and F. The pivotally-mountedpolarized armature j is normally retracted away from contactmakingposition, as in the system of Fig. 1, while the main armature tendsalways to fall by gravity or other suitable constant retract- Jive forceaway from its front coils E F and toward its back magnet G, so that suchmain armature is not wholly dependent upon the back magnet G for itsretractive force, although such back magnet G when energized reinforcesthe constant retractive force tending to retract the main armature. Themain armature controls its contact-fingers m 0 and 45, so as to move thecontact-fingers m and 0 into contact, respectively, with thecontact-stop n and the contact-sprin 1), while moving the contact-finger45 out of position of contact with its cooperating contactspring 46.Reversely, the retractive movement of the main armature breaks the contacts m n and 0 p, while closing the contacts 45 46.

Each. signaling apparatus interposed between successive blocks comprisesa relay restoring battery, such as 44, the current of the batterythrough. its external circuit being directionally controlled by a rearpolechanger including contact-fingers 38 and 41, actuated by a rearpole-changer armature,

- not shown in the diagram,but controlled by a .slow-actmg rearpole-changer magnet A, so

that after the magnet has been energized it will attract its armature soas to move its contact-fingers 38 and 41 into contact with theirrespective cooperating contact-stops 39 and 42, and after the magnet hasbeen deenergized for a short period of time it will release its rearpole-changer arniature, which will then be retracted by gravity or anyother suitable constant retractive force so as to reverse the positionsof its contact-fingers 38 and 41 and bring them into contact,respectively, with their cooperating contact-stops 40 and 43 in lieu oftheir respective contact- Therear pole-changer mag matures andpole-changer contact-fingers are therefore normally in retractedpositions.

The track-circuit pole-changers of Fig. 2, which may now be termed theadvance pole-changers in contradistinction to the rear pole-changers ofthe system of Fig. 2, corre spond in connections, functions, &c., to thesemaphore-actuated pole-changers of Fig. 1; but in the present instancesuch track-circuit pole-changers or advance pole-changers are operatedby advance pole-changer armatures, not shown in the diagram, butactuatedby advance pole-changer electromagnets, such as C, normallydeonergized, but controlled by a local circuit in a manner which is tobe fully described hereinafter. In

addition to operating the contact-fingers 2 and 6 of its pole-changer atthe advance end of the block B the armature of the advance pole-changermagnet also operates an additional contact-finger c, cooperating withthe contact-stop c. Normally'that is to say, when the pole-changermagnet C is deiinergizedthis contact-finger 0 makes contact with itscontact-stop c, while the contactfingers 2 and 6 of the advancepole-changer make contact, respectively, with their cooperatingcontact-stops 4 and 7. The contact-fingers 0,2, and 6 are normally heldin. such normal positions by suitable retractive means, not shown in thediagram, but efl'eetive to draw such contact-fingers into their normalpositions when the advance polechanger magnet is deinergized. When theadvance pole-changer magnet is energized, its armature is attractedthereby so as to move its contact-finger 6 out of position of contactwith its cooperating stop c, while moving its pole-changerconta'ct-fingcrs 2 and 6 out of contact with their respective stops 4and 7 and into contact with their respective stops 3 and 5.

Each signaling apparatus interposed between successive railway-blocks ofthe system diagramined in Fig. 2- comprises two semaphore-actuatedcontact-levers, such as w and 36, cooperating, respectively, with acontact-stop 0c and a contact-spring37. Normallythat is to say, when thehome-signal semaphore H is in its danger position thesesemaphore-actuated contact-levers are out of contacting positions; butas the home-signal semaphore is moved to its clear position thesemaphore-actuated contact-levers 36 and w are moved into contactingpositions, the conta:ctlevers 36 first making contact with itscooperating contact-spring 37, and. the contact-lever w making latercontact with its cooperating contact-stop at, so that when thehome-signal semaphore has attained its extreme clear position. both ofits semaphoreactuated contact-levers are in contacting positions. Ofcourse when the home-signal semaphore is moved again to its dangerposition its semaphore-actuated contact-levers are by such movement ofthe semaphore retracted from their contacting positions.

We may now consider the circuits and circuit branches which cooperatewith or are comprised in the track-circuit of any block of the system,taking, for example, the block B, since all of the circuits and circuitbranches of this block are illustrated in the diagram. An advancetraclcbattery, such as 9 ,is located at the advance end of each blockand corresponds in all respects to the advance track-batteries of thesystem of Fig. 1. Exs cepting, of course, the connections dispensed withpursuant to dispensing with the resistances, such as R of Fig. 1, as hasbeen already explained, the advance track-battery 9" and TCO leadsthrough the front coils K 1 of the advance track-relay Y andthence'through the l its advance track-relay Y are connected to- 'getherand through the advance pole-changer to the advance ends of the rails ofthe block Bf, all in the manner which has already been described Withrespect to the corresponding connections'of the system of Fig. 1, andsuch advance track-battery and advance trackrelay and advancepole-changer and all the connections thereof also correspond opefra tionand cooperation to the corresponding elements of the system of Fig. 1,so that the advance end of the left rail Z of the block B normallyleads-through the advance polechanger to the negative pole ofthejadvanjce trackb attery, hile the positive pole thereof advancepole-changer and'normally to the z advance end of the right rail. 1" ofsuch block,

theadvance ends ofthe rails of the block B being thereby normallycharged by the ad Vance track-battery, 9 with electrornotive force,having .the home clearing direction :or polarity.- The connections atthe rear end of the blookB arehowever, different from thie rear endconnections of theblocksof thesysithsuch spring and controlled bythemain armature of the ,rear track-relay X ,of the block B and .from' suchcontactfinger 45 through conductor 32 to thepositive pole of the reartrack-battery orrelayrestoring battery 44, thence through suchlbatteryto'iits negative pole, and from the negative pole thereof throughconductor .33, "contact-stop 4'3 ofthe rear pole-changer, itscontact-finger, 41, normally in contact therewith, conductor 18, thetwohack coils G of the back magnet of the reartrack-relayX thecircuitleading through such back coils in'seriesWith-each' other, andthence leading through conductor 19 to the rear end of the left rail. Zof the block B With which rear'end such condu'ctorl 9fis connected. It'Will be noted tha t'the foregoing rear branch of the track-circuit ofthe block B includes its rear track-battery or relay{restor ingbattery44 with the rear end" of the, right rail of the block leadingnormallythro igh the re ar pole-changer into the positive pole of suchpole thereof leads normally through such rear. pole-changer'andthe'back'coils to the rear n of h l jtha i. h ree re r 'arelay-restoring battery, While :the' negative t'ery or relay-restoringbattery 44 normally v chargesthe right and left railspositiv'ely andhegatively, respectively, and tends to force current throughitsrearbranch of the track :circuit and ,th roughsuch rails thereof in adirection "opposed to the direction in which the advance trackbattoly Stcnds to force current through such rails. Thus the fear or lrel ayrestoring battery 44 constitutes a counter or opposed electromotiveforce inthe track-circuit or track branch of the advance track battery9*, the result being to reduce the effective conductance of the trackcir- 'cuit of the block B and thusv maintain in ,1

rammed positions both the homeclearirig and the home and distantclearing armatures of the advance track-relay Y of such block and inamanner Whichhas already I een aaflyd sc wi esp 'ct oth fif' tractive'effect of lthe momentary relay-rei i 1 nd e e f the se phi ieafiiiatingor relay-restoringbatteries, such as 8,

thereof. The advance track-battery 9 the rear track battery orrelay-restoring bat t y f m yb alane i e r'e eq ro- 'Ino ti veforcesthat neither battery forces'an'y c s delrabl mo of urr t o ghtrackcircuit of theblock B in oppo siitionito the other battery, theeffect asregards consumption of current behig that o f' theinore Fig.1.- Of course some current mavjnojw from either or both batteriesthroughiithe leakage branch of their common track-cir- IQO cuitibutsuchcurrentvvill not sufiic'ientljto effectany attracti on oftheirar'matu'reof the advance track-relay lYfijnor will it in any l i e afist re r e ay X n e iy j'ciirrent pa'ssing'f through the rear branch" ofthe scribedasincluding itsback'jcoilsjGfcan only have the, effect ofenergizing such back coils an ialis g' he t o t an armada ,of the re r.track relay 1X still more' iirmlyi its normallretracted position.

W y n w n de h ope atio Qtth y' t mdiag m d i Z Q I I iQi fih 'tiorls ilt h hfi ei th Progr v 'j merit of a railway rtrain al ong'the'ra'ilwaand toward. the block B and" from a po nt frearthereof."

with an investigation of the sequen'ce of I m y tie-as u the r lweyt aior vehicle is presentin the blockinrear of, the

bloc'kB land ispro ceeding tovvarditheiblock gB. The "presence of's'uchtrain for vh'ic1e' in the block in rear of the block B will ,have

s iQrt circuite d the "rails of "such rear blbbk- T lay at theadvanceend of suchrear' block, so

Land vvill have actilated theadvance track-rethat' the home clearingcoils and theihorn'je fand distaritel aiing coils and the coils of thereartrackfrelay atthe rear end ofthe 'ble kiBreerres e in .teereetir t 5storing currentemployed in the system of later be developed with respectto the presence of a train in the block B and the effect thereof uponthe advance track-relay Y and the rear track-relay X located at theadvance and rear ends of the blocks B and B res ectively. Suchconnection of all the coi s of the rear track-relay of the block B inthe rear end of its track-circuit so increases the conductance of suchtrack-circuit that the home clearing relay-armature of the ad vancetrack-relay Y at the advance end of such block is attracted toward thefront coils K J of such advance track-relay, all in the manner and forthe electrical and magnetic reasons already set forth in connection withthe corresponding operation of the advance track-relays of the systemdiagrammed in Fig. 1. Such attraction of the home clearing-armature ofthe advance track-relay Y brings its contact-finger f into contact withits cooperating contact-stop g, and thereby closes a circuit local tothe signaling apparatus at the advance end of the block B, such localcircuit being a local circuit of the relayrestoring battery or reartrack-battery 44 including the home clearing coilsE of the trackrelay Xconnected to the rear end of the track-circuit of the block B Such localcircuit is traceable as follows: from the positive pole of therelay-restoring battery 44, through the conductor 32, contact-finger 45,its cooperating contact-spring 46, with which the contact-finger isnormally in contact, conductor 34, rear pole-changer contacts 40 38,conductor 16, contact-stop 9, its cooperating contact-finger f, whichhas just been moved into contact therewith, conductor 17, the two homeclearing coils E in series with each other, conductor 18, normalpole-changer contacts 41 43, and conductor 33, back to the negative poleof the relay-restoring battery. Such closingof the contacts f g, whichintroduces the home clearing relay-coils E into a local circuit of therelay-restoring battery 44, also introduces such home clearing coils Einto the rear end of the track-circuit or track branch of the advancetrack-battery 9 of the block B such rear home clearing coils E beingintroduced in parallel with the relayrestoring battery 44 as regards thecircuit relationship of such coils and battery to the track-circuit ofthe block B the rear branches of such track-circuit being now traceableas 5 follows: from the rear end of the right rail of the block B whichright rail leads from the positive pole of the advance track-battery 9,through the conductor 1 6, and thence through two parallel branches tothe conductor 18 one of such parallel branches leading from theconductor 16, through contacts g f, conductor 17 and rear home clearingcoils E to the conductor 18, and the other branch leading from theconductor 16, through the normally closed rear aole-changer contacts 3840, wire 34, normally closed contacts 46 45, controlled by the reartrack-relay X, wire 32, to the positive pole of the relay-restoringbattery 44, and thence through such relay-restoring battery in adirection opposed to the direction of its own polarity and to theconductor 33, and thence through the normal rear pole-changer contacts43 41, to the eonductor 18, where the two branches reunite and fromwhence the track-circuit of the block B continues through the back coilsG of its rear track-relay and through conductor 19 to the rear end ofthe left rail 1 of the block. From the foregoing it will be apparentthat the home clearing coils E of'the rear track-relay X of the block Bare included both in a circuit of the relay-rcstoring battery 44 and ina circuit of the advance trackbattery 9 and that both these batteriescoordinately or conjunctively tend to induce current in one commondirection in such home clearing coils or front coils E, although the twobatteries are still opposed in the respective directions in which theytend to induce current in the back coils G of the rear trackrelay Xwherefore the home clearing front coils E of such rear track-relaypreponderate in their magnetic attraction upon the main armature thereofand raise the main armature to its attracted position or position ofnearest approach to such home clearing front coils E and to the home anddistant clearing front coils F. Such attraction of the main armature ofthe rear track-relay X closes its contacts m n 0 p and after the mainarmature has passed through a portion of its movement toward the frontcoils opens its contacts 45 46. The spring-contact 46 follows the firstportion of the movement of its cooperating contact-finger 45, so thatthe rear branch of the track-circuit of the block B, including suchcontacts 45 46 and including the rear track-battery 44, will not bebroken until the main armature of the relay has been moved aconsiderable distance away from its backcoils and toward its frontcoils. After such rear branch of the track-circuit, including its reartrack-battery 44, is broken the home clearing front coils E of the reartrackrelay X andthe back coils G thereof remain connected in series witheach other in a single rear branch of the track-circuit traceable asfollows: from the rear end of the right rail r of such track-circuit,through the conductor 16, contacts gf, conductor 17, home clearing frontcoils E, conductor 18, back coils G and conductor 19, to the rear end ofthe left rail l of such track-circuit. The rear track-battery 44 nowbeing completely out of circuit,

TOO

